1. Field of the Invention
This invention relates generally to a pipe fitting alignment method and, particularly, to use of an alignment system which employs a tool that projects a highly focused or collimated beam of light.
2. Discussion of Relevant Art
Several constructions exist in the art for the alignment of conduit, such as sprinkler or sewer pipes, that employ coherent light sources and various target apparata. Most relevant to the instant invention are U.S. Pat. No. 3,631,601 ('601), No. 4,968,147 ('147), and No. 4,681,439 ('439).
Patent '601 employs a laser beam to set a series of pipe sections in place along a predetermined line and grade by mounting the laser projector inside of a first pipe section preset on the desired line and grade by conventional surveying techniques. Using adjusting screws on its mounting housing, the laser projector is set within the first pipe section and precisely centered on a remote target position on the proper grade and line. With a laser beam projecting down the desired pipeline, at the proper grade angle, successive pipe sections are set in place by placing the target within each successive pipe section and moving each pipe section laterally or vertically as required to center the target on the laser beam. Thus, there is disclosed a laser projector, free-standing within a pipe section, an auxiliary power supply for the laser projector and, at least one pipe section embracing a moveable target therein. Notable incidents of this disclosure are: the projector is set inside the pipe bore, in fact, entirely enclosed within the bore; there is no alignment with the central axis of the pipe or conduit itself; and, the procedure is extremely labor intensive.
Patents No. '147 and '439 are issued to the same inventor and disclose a target insert for use with a laser aligning system and a pipe laying method and apparatus, respectively. Of '147, a base target apparatus is disclosed for aligning a length of pipe along the longitudinal axis of a pipe string wherein the target apparatus includes a base unit, containing a target unit, and having one tapered end which is dimensioned to be received in the bell end of the pipe. The other end of the base unit is provided with an anchor unit which is dimensioned to be fictionally engaged in the spigot end of the length of pipe. The target disclosed is square in geometry and bears thereon a set of crosshairs or indices. It is captured in a hoop, that is secured to a spigot end of a pipe, so that the target is presented in a plane transverse to the pipe centerline. To the extent that the target is embraced by the pipe, or a stylized extension thereof, it is analogous to the '601 apparatus. In a not too dissimilar vein, '439 discloses a method and apparatus which are employed to give the operator of excavating equipment a quick and accurate visual indication of the amount of excavation required to obtain a desired grade level. The apparatus comprises: a laser unit; a representative pipe section; a centerline target unit; and, a grade checker unit. Alignment of a laser beam projected from the laser unit to selected portions of a stationary target element and of an adjustable target element, on the centerline target unit and the grade checker unit respectively, determines the desired grade depth. The significant aspects of '439 are: the laser unit is a free-standing projector, that is, it stands on the grade or ground over which the pipe is to lay; the centerline target unit is embraced by the representative pipe section; and, the stationary target element is placed downrange of the laser beam, is free-standing and contains adjustable panels within its framework. The method of applying '439 is practically identical to that of '601, the exception being that rather than place sections of the pipe in the downrange centerline of the projected beam, a plurality of targets, adjustable to give the laser beam observer an indication of how high or low a particular targets's base index is off the laser beam centerline, is deployed. Once the positions are denoted and the proper reference depth is read, excavation is commenced to the proper grade and depth so that the selected pipework may lay coaxially along the laser beam downrange centerline. As in '601, the method and apparatus of '439 is extremely labor intensive.
Although the aforementioned systems are of significant value in their work environment, what is needed for the lone individual tradesman is a pipe fitting alignment system that is less costly to realize and set up, less time consuming to align and is within the capability of a single person to use.
3. Incorporation by Reference
In order to make the instant disclosure completely comprehensive with respect to the field, U.S. Pat. No. 3,631,601, No. 4,968,147 and, No. 4,681,439 are hereinafter incorporated by reference.